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William Optics ZS61 strange star "spikes"

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Hello all , finally i got WO zenithstar 61 + dedicated flattener so i went to test it and there are strange "spikes" or darker shadows around all brightest stars.What causes the and how to get rid of them ?Its bit annoying .
Setup used for test shot was ZS61+Flat61 connected to canon 800D via m48 adapter.
Any help and ideas will be appreciated.

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I’m not familiar with the WO scopes but I had a similar problem with my old Vixen refractor. In my case, the three black “notches” in really bright stars seemed to be caused by shadows of the edges of some clips that formed part of the primary lens assembly. Look down the front of your scope and see if you can see anything like that. I cut a thin circular gasket out of black card and sat it on the primary so that the clip edges couldn’t be seen. Problem solved. Apologies in advance if this is completely irrelevant to your situation.

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Thanks for replies. I unscrewed the dew cap and bingo there are 3 places with double screws in that shape . Which one do I have to unscrew upper or lower ones ? The lower screws are glued but upper ones aren't .

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As always when you buy new toy or it's starting to work as intended after tuning or tweaking the weather have to gone crazy So currently i have 100% clouds Maybe tommorow i have some hole in sky for 4 hours and will test it. Surely will post test results here if everything goes well

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Thanks for replies. I unscrewed the dew cap and bingo there are 3 places with double screws in that shape . Which one do I have to unscrew upper or lower ones ? The lower screws are glued but upper ones aren't .

Ok not that I want to cause panic but those are the factory set lens alignment screws, if you had not already done it I would be screaming at you not to touch them. If you now find that your corner stars are odd shapes then altering those screws could be the cause. They glue them because they are never supposed to be moved by the user.

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Still waiting for clear skies, but i think i wont be able to cjeck it on real star test for 1 week or longer because the weather goes crazy But i made a artificial star from fiberoptic and after testing i think its ok but this was tested in + temps so need to check it again after cooling it to minus temps. I found somewhere here on forum similar problem with some WO scopes and there was same pattern on stars and it happened only when scope was exposed to minus temperatures (winter) and no problem at summer. SO it looks like the lens get pinched when exposed to minus temperatures. The only idea to avoid this is to use dew heater that will warm lens assembly .